(a) Field of the Invention
Embodiments of the present invention relate generally to flat panel displays. More specifically, embodiments of the present invention relate to thin film transistors for use in flat panel displays, and manufacturing methods therefor.
(b) Description of the Related Art
In general, thin film transistors (TFTs) are used as switching elements in an image display device or a semiconductor device.
In a display device, the thin film transistor (TFT) is generally formed at an intersection of a gate wire and a data wire. The gate and data wires define unit pixel areas, and supply current for turning the unit pixel area on or off. In an on state, current flows such that a capacitor related to the corresponding unit pixel area is charged to a desired voltage, and in an off state, the charged state is maintained until the unit pixel area is next addressed. At this time, a voltage level determines an amount of light passing through a liquid crystal corresponding to the unit pixel area, thereby determining a gray level.
The thin film transistor may be used as a switching element for the liquid crystal display. Recently, the tendency toward large size liquid crystal displays and highly miniaturized circuitry has accelerated, requiring next generation processes for realization thereof.
Particularly, if very high resolution and a high speed driving are applied to a large size display, it is often desirable for RC delay to be reduced and the characteristics of the thin film transistor to be improved with regard to the driving of the panel. For this, a technique using an insulating layer having a low dielectric ratio to reduce parasitic capacitance between wires and to reduce the RC delay is applied, however, this may decrease on current in a channel region.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that is not in the prior art.